One of the problems with surgical procedures, such as laparoscopic surgery and the like, is the disposal of surgical waste gas generated during the surgical procedure. Douglas Ott of Georgia Biomedical addressed the contamination of the insufflation gases directed into a body cavity with a CO2 Guard Filter, which is a 0.2 um particulate filter that is used to filter the insufflation gas injected into a body cavity during surgery. Others have addressed the problems with surgical waste gas generated in a body cavity during the surgical procedure. These surgical waste gases, which can contain harmful materials, are often discharged directly into the operating room prior to or at completion of the surgical procedure.
It is known that smoke created during surgical procedures and subsequently discharged into the operating room as part of the surgical waste gas poses a health problem for operating room staff. The smoke can result in infections, lesions on the throat and nose, as well as health problems associated with the inhalation of noxious gases such as carbon monoxide, acid gases including formic acid, and hydrocarbon vapors such as formaldehyde, which are present in the smoke. Smoke evacuators have been used by surgeons and operating room staff members for both general surgery and laparoscopic surgeries to address the problem of discharging surgical waste gas containing smoke.
While surgeons have vented the surgical waste gas from the peritoneum directly into the operating room without filtering it Dr. Joxel Garcia in U.S. Pat. No. 5,722,962, discloses a trocar mounted filter to address the venting of surgical waste gas from the peritoneum into the operating room with the trocar mounted filter including two filter elements to remove large and small particles from the surgical waste gas. Surratt et al in U.S. Pat. No. 5,688,256, also discloses an invention that controls the flow rate of the surgical waste gas exiting the peritoneum while also filtering the surgical waste gas.
The above identified particle filters do not address the contamination associated with odors in the surgical waste gas. However, U.S. Pat. Nos. 6,110,259 and 6,589,316, Schultz disclose a smoke evacuator filter with a particulate filter media in addition to an odor removing media. Schultz acknowledges that smoke odor can also be a problem for surgical staff and or staff members. Schultz addresses the issue of odor removal through the use of activated carbon. Similarly, in U.S. Pat. No. 6,576,033, Booth discloses a Filter for Use in Medical Procedures that uses an activated carbon bed to remove odors associated with laser surgery.
A study entitled Smoke Production and Smoke Reduction in Endoscopic Surgery: Preliminary Report by Dr. Douglas Ott, identified a list of toxic chemicals generated by pyrolysis of protein and lipids during laser surgery including: Acroloin, acetronitrile, acrylonitrile, acetylene, alkyl benzenes, benzene, butadiene, butene, carbon monoxide, creosols, ethane, ethane, ethylene, formaldehyde, free radicals, hydrogen cyanide, isobutene, methane, pheonal, PAH's, propene, propylene, pyridene, pyrrole, styrene, toluene and xylene.
These chemicals are considered to be toxic by various agencies including NIOSH<EPS, ACGIH and OSHA. Odor removing media referenced by the above identified prior art includes activated carbon, which will remove most “C4 and heavier hydrocarbons, ketones, alcohols, esters, ethers, organic acids and chlorinated organics, Freons, all aromatic hydrocarbons, carbon disulfide”. Little or no adsorption with activated carbon occurs on organic compounds lighter than C3. These chemicals include “carbon monoxide, amines, ammonia, acetylene, most C and lighter hydrocarbons, sulfur dioxide.” Molecular Sieve Type 4A will remove carbon dioxide, ammonia, sulfur dioxide, hydrogen sulfide, acetylene, propylene, methane, ethane, water vapor, ethylene, ethylene dioxide, carbon disulfide. Molecular Sieve Type 13X is recommended for the removal of methanol, straight chain mercaptans, Freon 11, Freon 12, Freon 114, sulfur hexafluoride, straight chain hydrocarbons to C22, cyclohexane, diphenyl, butene-1, isopentane, benzene, toluene, xylene, boron tridfloride, triethylamine and smaller amines. Calgon Type GHR Sulfur Impregnated Carbon is recommended for the removal of mercury vapor. Sodium and Calcium Hydroxide is recommended for the removal of all acidic gases. See Balston Adsorbents Used in Type C1 Cartridges. Acid gases can also be present in which case, (a mixture of calcium and sodium hydroxide) can be used.
Carbon monoxide is a colorless, odorless, poisonous gas the significance of the surgical waste gas can be overlooked. As a result what has been failed to be addressed in the above inventions is the removal of an odorless, poisonous gases such as carbon monoxide from the surgical waste gas. Dr. Douglas Ott provides a study entitled Carboxyhemoglobinemia Due to Peritoneal Smoke Absorption from Laser Tissue Combustion at Laparoscopy. Ott points out that carbon monoxide is a respiratory poison that can directly affect the respiratory system by absorption of carbon monoxide gas. Carbon monoxide is known as a byproduct of incomplete combustion of a carbon containing material. In the Ott study, smoke was sampled on the exhaust side of a trocar. Two minutes after laser surgery, intra-abdominal carbon monoxide increased to 425 ppm. The peak concentration observed was 60 times the recommended exposure limit by the EPA.
Currently carbon monoxide gas from the surgical waste gas is discharged into the operating room without any means of removing the carbon monoxide gas from the operating room although other contaminants are removed from the surgical waste gas before discharging the surgical waste gas into the operating room. The invention described herein addresses the problem of removal of carbon monoxide from a surgical waste gas before the surgical waste gas is vented to the operating room.